Field of the Invention
This utility model involves the technical aspects of an umbrella, especially the technical aspects of the umbrella rib structure; this utility model specifically refers to the telescopic tube structure of an umbrella rib.
Description of the Related Art
The canopy of the majority of existing collapsible umbrellas is supported by several ribs, in order to achieve a shading effect. The tightness of the canopy needs to be adjusted over time as the canopy would become loose as a result of prolonged use. There are some telescopic rib structures available in the market, for example, the umbrella disclosed in patent ZL200810074398.8, of which only the long rib is equipped with a spring to adjust the inner rib of the long rib. Such an arrangement can only adjust the tightness of the canopy, but not allow for the inner bone of the rib to be retractable. Another example is the collapsible ribs of the sunshade disclosed in patent ZL01267618.7, of which the long rib is equipped with a flexible button to adjust the stretching and retracting of the inner rib. It is extremely inconvenient having to locate the button after installing the canopy to stretch or retract the inner rib of the umbrella rib. Thus, an adjustable telescopic tube structure of an umbrella rib is required. The structure must not only solve the problem of adjusting the tightness of the canopy, but must also be applicable to the retracting of the relatively long ribs during the closing of rectangle umbrellas, so as to overcome the height difference between the long umbrella ribs and the table below the umbrella.